The present invention relates to gas burners and, in particular, to a burner for research purposes, which permits ready optical study of the pre-combustion and primary reaction zones of adiabatic flames of combustible gas mixtures.
The reaction chemistry of flames has been the subject of considerable investigation. These investigations have generally focused attention on the thin primary reaction zone, which is typically of the order of 100 um thick for a near stoichiometric flame at atmospheric pressure. Burners employed in the past for studying these systems have generally utilized an array of tubes or the like, sintered porous metal disks, a metal screen or plate, or some other physical barrier to establish a stable flame. All of these methods and devices result in extraction of heat from the flame, the amount dependent upon several physical parameters. In a typical configuration, a stable flame requires that the primary reaction zone be seated on the burner surface; however, this position renders access to the primary reaction zone quite difficult at atmospheric pressure. Low presure chambers have been frequently used to expand the flame zones.
A burner useful for laser probing of flame systems has been recently developed. The burner utilizes a knife edge and a precision machined surface to provide a non-adiabatic flame which can be studied by laser spectroscopy through the primary reaction zone. (D. A. Stephenson, "Non-Intrusive Profiles of Atmospheric Premixed Hydrocarbon-Air Flames:, 17th Symposium (International) on Combustion, Leeds, England, P. 993, 1978).
Accordingly, There is a need for a research type burner which permits ready optical access to the precombustion and primary reaction zones of adiabatic flames of combustible gas mixtures.